This invention relates to apparatus for retrieving the tow lines of marine vessels such as barges and ships which have broken loose from a towing tug, leaving their tow lines dangling freely in the water.
In the operation of tugs and barges, particularly of ocean going tugs and barges, use is made of a nylon or cable tow line connected to the barge through a chain bridle. Because of the heavy loads imposed upon it, it is not uncommon for the tow line to break.
Since this mishap often occurs under storm conditions, when the winds are high and the seas are mountainous, the recapture of the towed vessel presents a serious and hazardous problem. A particular problem is presented for the reason that in the usual situation crewmen are not aboard the towed vessel. Barges customarily are unmanned when they are under tow.
Accordingly, one method of recapturing a barge which has broken loose from its tug is to transfer one or more crewmen from the tug to the barge, and then re-establish the tow by the use of heaving lines. In view of adverse weather and sea conditions, this is a difficult and dangerous assignment which may be impossible of fulfillment until the prevailing conditions of sea and weather have improved. It also may leave the crewmen aboard the barge for the duration of transit, under uncomfortable and unhealthful conditions.
A second method of recapturing a barge which has broken loose is through the use of an "insurance line".
This method is used widely at the present time. It requires the use and continual presence on the barge of an auxiliary or spare barge-towing cable tacked to the deck of the barge. One end of the towing cable is connected to the conventional bitt located off center on one side of the barge for attachment of one leg of the conventional towing bridle. The other end of the cable is coupled to a float-towing line which trails behind the barge when the barge is underway.
If the working tow line should break, the tug circles the barge, picks up the float-towing line, rips loose the spare towing cable from the barge deck, and couples it to the residual working towing cable. It then proceeds with the tow, using the "insurance line" as the tow cable.
This system has at least two serious defects.
First, since the "insurance line" on the deck of the barge is continually exposed to the elements and to salt spray, it corrodes rapidly and often is in no condition for service when the emergency arises. Upon being connected to the working towing line of the tug, it breaks and the problem of a loose barge is still present.
Second, even if the "insurance line" is in good condition and does not fail, it tows the barge in a unsatisfactory and sometimes dangerous manner.
As noted, the barge end of the "insurance line" is fastened to one of the off-center towing bitts of the barge to which one leg of the barge-towing bridle is connected. Accordingly, when the barge is towed by the single "insurance line", connected off-center of the barge, the barge tends to shear and will not tow straight. As a result, it is difficult to control.
It accordingly is the general object of this invention to provide an assembly for retrieving broken towing lines from barges and ships and to reestablish the tow.
Other objects are the provision of such an assembly which is characterized by the following advantages:
1. Continuously functional. PA1 2. Free from the danger of damage by exposure to salt water. PA1 3. Easy and safe to use. PA1 4. Avoids the necessity of transferring crewmen to the derelict barge. PA1 5. Establishes a strong hookup with the barge. PA1 6. After re-establishment of the tow, pulls the barge efficiently from the center so that it does not shear when underway. PA1 7. Capable of use under adverse weather conditions and in high seas. PA1 8. Has a long service life.
The foregoing and other objects of this invention are achieved by the provision of an assembly which, generally stated, comprises hook means dimensioned to receive and engage the chain bridle component of a broken barge tow line, float means connected to the hook for maintaining it at a predetermined distance below the surface of the water, and a hook towing line connected to the hook means for deploying it into position for intercepting and engaging the bridle. The assembly includes hook positioning means connecting the hook to the hook towing line. This serves to position the hook in engaging position relative to the bridle.
The device normally is stowed away aboard the tug. When the occasion for its use arises, it is thrown overboard and its tow line paid out. The tug encircles the derelict vessel until the hook engages the chain bridle dangling from the bow of the barge or other vessel under tow. The tow then can be continued in normal manner.